1. Field of the Invention
This invention relates to a display device.
2. Description of the Related Art
As display devices such as information communication terminals including computers and television receivers, liquid crystal display devices are widely used. Further, organic EL (Electro-Luminescent) display devices are also known as thin display devices. The display panel of the thin display device performs display by operating TFTs (Thin Film Transistors) formed on respective pixels of a display area on a substrate. Here, the TFT is driven by a drive IC (Integrated Circuit) as a semiconductor integrated circuit element mounted outside of the display area, and generally, the terminal of the drive IC (bump) and wiring on the substrate are connected using an anisotropic conductive film (ACF) or the like.
JP 2008-172138 A discloses junction between a pattern electrode formed on a glass panel and a pattern electrode formed on an FPC (Flexible Printed Circuits) using a UV (Ultra Violet) curing material.
In related art, the wiring of the display device and the terminal (bump) of the drive IC or the terminal of the FPC are pressure-joined using a thermosetting anisotropic conductive film. However, with the thermosetting anisotropic conductive film, the display panel can be warped due to heat at pressure-joining and luminance unevenness is caused in display of the display device. Further, when a touch panel is attached onto the display panel, stress distributions are biased in both the touch panel and the display panel due to warp of the display panel, and further luminance unevenness etc. are caused. On the other hand, in a sheet display having a substrate of the display device formed using a flexible or bendable material, the substrate largely deforms due to heat and it is difficult to directly use the thermosetting anisotropic conductive film.
Here, an ultraviolet curing anisotropic conductive film requires the lower heating temperature than the thermosetting anisotropic conductive film, and, as a solution to the above described problem, use of the ultraviolet curing anisotropic conductive film cured by application of ultraviolet light is considered. However, the terminal on the substrate is formed using a light-blocking metal, and there may be locations in the anisotropic conductive film without sufficient application of ultraviolet light and reliability of connection may be insufficient.